AJP - Renal Physiology, Vol 251, Issue 5 817-F821, Copyright © 1986 by American Physiological Society
Release of atrial natriuretic factor. Effects of repetitive stretch and temperature
G. E. Bilder, T. L. Schofield and E. H. Blaine
The effect of continuous and repetitive mechanical stretch on release of
immunoreactive atrial natriuretic factor (IR-ANF) was studied in isolated
rat atria distended by inflation of miniature balloon catheters. After 10
min incubation, the concentration of IR-ANF in the medium increased in
proportion to the degree of continuous atrial stretch. Repetitive atrial
expansion induced a rate dependent increase in release of IR-ANF which at
the highest rate tested (89 inflations/min) was sixfold greater than that
observed with continuous maximal expansion. Comparison of the amount of
IR-ANF released from the right or left atrium separately revealed that
during continuous and repetitive stretch, both atria contribute equally to
the total amount of release IR-ANF. A reduction of bath temperature (37
degrees to 21.5 degrees C) decreased both basal- and stretch-induced IR-ANF
release approximately 85%. It was concluded that release of atrial
natriuretic factor is temperature-dependent and induced by both the extent
and rate of atrial stretch.
